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While the term chemical substance is a precise technical term that is synonymous with chemical for chemists, the word chemical is used in general usage to refer to both (pure) chemical substances and mixtures (often called compounds), [14] and especially when produced or purified in a laboratory or an industrial process.
A diagram representing at the microscopic level the differences between homogeneous mixtures, heterogeneous mixtures, compounds, and elements. Mixtures can be either homogeneous or heterogeneous: a mixture of uniform composition and in which all components are in the same phase, such as salt in water, is called homogeneous, whereas a mixture of ...
chemical substance. Also pure substance or simply substance. A form of matter that has constant chemical composition and characteristic properties and which cannot be separated into simpler components by purely physical methods (i.e. without breaking chemical bonds). It is often called a pure substance to distinguish it from a mixture. chemical ...
If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. [16] Chemical substances can exist in several different physical states or phases (e.g. solids, liquids, gases, or plasma) without changing their chemical composition.
Chemists and nuclear scientists have different definitions of a pure element. In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one isotope. [18]
Since neither element has a stronger affinity to donate or gain electrons, it causes the elements to share electrons so both elements have a more stable octet. Ionic bonding occurs when valence electrons are completely transferred between elements. Opposite to covalent bonding, this chemical bond creates two oppositely charged ions.
A separation process is a method that converts a mixture or a solution of chemical substances into two or more distinct product mixtures, [1] a scientific process of separating two or more substances in order to obtain purity. At least one product mixture from the separation is enriched in one or more of the source mixture's constituents.
Firstly, a pure chemical should appear in at least one chemical phase and can also be characterized by its phase diagram. Secondly, a pure chemical should prove to be homogeneous (i.e., a uniform substance that has the same composition throughout the material [2]). The perfect pure chemical will pass all attempts to separate and purify it further.